FIGS. 1-4 show a known fixation bracket for mounting a circuit board thereon.
As shown in FIG. 1, the known fixation bracket includes a pair of longitudinal beams 110′ and a pair of end plates 120′. The pair of longitudinal beams 110′ extends along a length of the fixation bracket. The pair of end plates 120′ is connected to ends of the pair of longitudinal beams 110′, respectively. A circuit board 200′ is mounted on the fixation bracket.
As shown in FIGS. 1 and 2, in the prior art, an elastic rail receiving structure 121′, 122′, 123′ is formed on a bottom of each end plates 120′. Each elastic rail receiving structure 121′, 122′, 123′ includes a pair of guide rail receiving slots 121′, 122′ and an elastic arm 123′. The pair of guide rail receiving slots 121′, 122′ are adapted to be snapped onto edges 321′, 322′ along both sides of the guide rail 300′. One guide rail receiving slot 122′ of the pair of guide rail receiving slots 121′, 122′ is formed in the elastic arm 123′. The pair of guide rail receiving slots 121′, 122′ is constructed to face to each other in a width direction of the fixation bracket.
As shown in FIGS. 1 and 2, in the prior art, the known fixation bracket further includes a connection arm 124′ connected to the elastic arm 123′, and the connection arm 124′ extends outwardly underneath the fixation bracket. The known fixation bracket further includes a protrusion 125′ protruding upwardly from an end of the connection arm 124′ and is positioned adjacent to an outer side of the known fixation bracket.
The known fixation bracket and the circuit board 200′ are mounted in a cabinet (not shown) of a control device. In practical use, in order to satisfy maintenance requirements, it is sometimes desirable to disassemble the circuit board and the known fixation bracket from the guide rail in the cabinet.
As shown in FIGS. 3 and 4, the protrusion 125′ protruding from the connection arm 124′ may be pried by the screw driver 400′ such that the guide rail receiving slot 122′ on the bottom of the fixation bracket is detached from the edge 322′ of the guide rail, thereby the known fixation bracket is disassembled from the guide rail 300′.
As shown in FIGS. 3 and 4, during disassembly, the screw driver 400′ needs to be rotated at a certain angle in a direction indicated by the arrow, that is to say, a receiving space must be provided for the screw driver 400′, or else the fixation bracket cannot be disassembled from the guide rail 300′. Thus, relatively large spaces for the screw driver 400′ at both sides of the fixation bracket are required, that is, no other components can be placed in the relatively large spaces along both sides of the fixation bracket, which thereby causes waste of space. As a result, the number of the circuit boards placed in the cabinet is limited. In addition, since the protrusion 125′ is located on the bottom of the known fixation bracket, the sight line is blocked by the known fixation bracket when an operator puts the screw driver 400′ onto the protrusion 125′, thus he or she must observe the protrusion 125′ from sides of the fixation bracket only by a particular angle, then put the screw driver 400 onto the protrusion 125′ carefully, thereby causing an inefficient and inconvenient operation.